Double Trouble: Hawaii Braces for Hurricanes Iselle and Julio

The first, Hurricane Iselle, packed 90-mph winds Wednesday night as it chugged west toward the islands. Meteorologists said it had strengthened somewhat and was expected to remain at hurricane strength when it makes landfall sometime late Thursday.

The trailing system, Hurricane Julio, was upgraded from a tropical storm Wednesday. Carrying 85-mph winds, it was expected to the north and clip Hawaii on Sunday night.

Mike Kelley, manager of the Cost-U-Less store in Hilo, told NBC station KHNL of Honolulu that the store had sold "a lot of rice, water, toilet paper. Bottled water was sold out, with no new shipments expected until Thursday or even Friday, he said

Hawaii is also holding primary elections Saturday for races including a Senate seat, the governorship and the House seat that represents Honolulu. Some islanders are voting early ahead of the weather.

When Isele strikes, "we'll have power outages likely from all the wind, and maybe some flooding, as well, from all the heavy rain," said Ari Sarsalari, a meteorologist for The Weather Channel.

The two tropical systems are being steered west toward the islands by the underside of a high-pressure system in the Pacific Ocean. A hurricane warning was posted Wednesday for the Big Island of Hawaii, and Maui, just to the west, was under a tropical storm warning. Kauai County was under a tropical storm watch.